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Karakteristik Struktur dan Listrik Film Tipis GaN yang Ditumbuhkan di atas Substrat Si(111) dengan Metode Plasma Assisted-Metalorganic Chemical Vapor Deposition (PA-MOCVD) Heri Sutanto; Agus Subagio; Edi Supriyanto; Pepen Arifin; Sukirno Sukirno; Maman Budiman; Mohamad Barmawi
Jurnal Matematika & Sains Vol 11, No 1 (2006)
Publisher : Institut Teknologi Bandung

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Abstract

Gallium nitride (GaN) thin films have been grown on Si(111) substrate by PA-MOCVD method, with trimethylgallium (TMGa) and radical nitrogen resulted by plasma of nitrogen gas as a source of Ga and N respectively. The growth was performed at 675 °C; 0.4 torr; 90 sccm and 0.08-0.12 sccm of substrate temperature, reactor pressure, gas flow of nitrogen and TMGa, respectively. The grown polycrystalline GaN thin films have hexagonal structure and n-type semiconductor. The growth rate of the grown thin films increased with increasing gas flow of TMGa. The Hall mobility value of films is still low due to the presence of O and C impurities. The highest value of mobility was found to be 64.88 cm2/V.s with 5.47 x 1018 cm-3 of carrier concentration.
N-Type Conductivity in Wurtzite Mn-Doped GaN thin Films Grown by Plasma Assisted MOCVD Budi Mulyanti; Agus Subagio; Edi Supriyanto; Heri Sutanto; Fitri Suryani Arsyad; Pepen Arifin; Maman Budiman; Mohamad Barmawi
Jurnal Matematika & Sains Vol 11, No 2 (2006)
Publisher : Institut Teknologi Bandung

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Abstract

Ferromagnetic semiconductor GaN:Mn thin films were successfully grown by plasma-assisted metalorganic chemical vapor deposition (PA-MOCVD) method on c-plane sapphire substrate. The films were grown at various Mn source flux in the range of 5 - 40 sccm and growth temperature which was lower than that of MOCVD themal, i.e. in the range of 625-700 °C. Cyclopentadienyl manganese tricarbonyl (CpMnT) was used as a source of Mn. X-ray diffraction patterns confirmed that GaN:Mn films are wurtzite and do not show second phase for film with Mn concentration up to 6.4% at 650 °C of growth temperature. Hall effect measurements show n-type characteristics. The carrier (electron) density tends to decreases and Hall mobility tends to with the increase of Mn concentration is increased. Hysteresis curves observed from VSM measurements indicated that all of the samples are ferromagnetic at room temperature.
Magnetoresistansi Divais Spintronika TiO2:Co/Si/TiO2:Co [Spintronics Magnetoresistance Device with TiO2:Co/Si/TiO2:Co] Edy Supriyanto; Agus Subagio; Hery Sutanto; Horasdia Saragih; Maman Budiman; Pepen Arifin; Sukirno Sukirno; Mohamad Barmawi
Jurnal Matematika & Sains Vol 12, No 1 (2007)
Publisher : Institut Teknologi Bandung

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Abstract

TiO2:Co thin films were grown on Si substrates by Metalorganic Chemical Vapor Deposition (MOCVD) technique using titanium(IV)isopropoxide and tris(2,2,6,6-tetramethyl-3,5-heptanedionato)cobalt (III), and oxygen gas. The films grown at temperature of 450 oC were crystalline having a rutile structure with (002) orientation. Based on Energy Dispersive Spectroscope (EDS) analysis, Co content in TiO2 was 1.83% and films exhibit ferromagnetic properties at room temperature. Hysteresis curves obtained from Vibrating Sample Magnetometer (VSM) measurement have coercive and saturation magnetic fields of 130 Oe and 2.1 emu/cm3, respectively. Application of TiO2:Co as injection material in spintronic device with TiO2:Co/Si/TiO2:Co structure was investigated. The effect of polarized spin injection (magnetoresistance phenomenon) was observed from the current-voltage characteristics of the device.
Pengaruh Temperatur Penumbuhan terhadap Struktur Kristal dan Morfologi Film Tipis TiO2:Eu yang Ditumbuhkan dengan Metode MOCVD [The Effect of Growth Temperature on the Crystall Structure and Morphology of the Thin Film TiO2:Eu Grown with MOCVD Method] Edy Supriyanto; Goib Wiranto; Hery Sutanto; Agus Subagio; Mikrajuddin Abdullah; Maman Budiman; Pepen Arifin; Sukirno Sukirno; Mohamad Barmawi
Jurnal Matematika & Sains Vol 12, No 2 (2007)
Publisher : Institut Teknologi Bandung

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Abstract

Thin film of TiO2:Eu had been grown on an n-type Si(100) substrate using Metalorganic Chemical Vapor Deposition (MOCVD) method with titanium (IV) isopropoxide [Ti{OCH(CH3)2}4] 99.99% and europium nitrate [Eu(NO3)3.6H2O] 99.99% as the metal organic precursors. The tetrahydrofuran (THF) was used as a solvent for the precursor. X-ray Diffraction (XRD) analysis showed that the TiO2:Eu thin film grown at temperature of 450 οC had crystal planes of rutile (200), rutile (002) and anatase (211), whereas film grown at 500 οC resulted in a crystal plane of rutile (002) with columnar grain and surface morphology relatively smooth. On the other hand, film grown at temperature of 550 οC has rutile (200) and rutile (002) planes. The surface morphology of thin films TiO2:Eu was affected by Eu atom concentration. The roughness of surface morphology increased with increasing Eu content and therefore the grains became larger. It can be concluded that the crystal structure and surface morphology properties of the films depended significantly on the substrate temperature.
Effectiveness of Boiling Method Using Aquadest Solvent in Oolong Tea Extraction Producing Mangenese Particle as a Contrast Media on Magnetic Resonance Cholangiopancreatography (MRCP) Fatimah Fatimah; Neni Susilaningsih; Hermina Sukmaningtyas; Agus Subagio
Medical Laboratory Technology Journal Vol. 7 No. 2 (2021): December
Publisher : Poltekkes Kemenkes Banjarmasin Jurusan Analis Kesehatan

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (328.55 KB) | DOI: 10.31964/mltj.v7i2.423

Abstract

Magnetic Resonance Cholangiography (MRCP) examines the pancreas and ductus billiaris using magnetic resonance imaging with a negative contrast media administered orally. Oolong tea is possible to be an alternative of an oral negative contrast media due to its manganese contained. This study will elaborate on the best method of oolong tea extraction to get the best mangenese substance and its capability to suppress inevitable organs. This is an experimental study with various methods of extraction, which are the maceration method with ethanol solvent, maceration method with aquadest solvent, and boiling method. The whole process includes collecting and preparing plant materials, sample identification, sample processing, extraction, and extract characterization. The manganese level is checked with Atomic Absorption Spectroscopy (AAS) followed by scanning the extracted oolong tea in bottles and MRCP scanning examination. Results showed that manganese level with three different extraction methods is maceration method with ethanol is 1.23 mg/dl, maceration method with aquadest solvent is 0.82 mg/dl, and the extraction using the boiling method with aquadest solvent 0.94 mg/dl, and manufactured tea 1.40 mg/dl respectively. Scanning the extracted oolong tea in bottles showed that the best suppression is on the bottle, which contains extracted oolong tea using a boiling method with aquadest solvent. The image enhancement on MRCP showed that biliary trees are all enhanced using all the extraction methods; however, the best suppression for the stomach and duodenum is using the boiling method with aquadest solvent. The best choice for oolong tea extraction to get the best image to enhance and maximum suppression for disturbing organs is the boiling method with aquadest solvent. For the oolong tea, oral media contrast is to consider the level of manganese substance and its capability to suppress the disturbing organ to provide the best image for MRCP
Nano-chitosan coating on maintaining the quality of postharvest chili pepper (Capsicum frutescens L.) Noor Laila Safitri; Erma Prihastanti; Sri Widodo Agung Suedy; Agus Subagio
Biogenesis: Jurnal Ilmiah Biologi Vol 9 No 2 (2021)
Publisher : Department of Biology, Faculty of Sci and Tech, Universitas Islam Negeri Alauddin Makassar

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24252/bio.v9i2.23524

Abstract

Chili pepper (Capsicum frutescens L.) is a horticulture product with a limited shelf life due to quality degradation following harvest. One method of preserving the quality of chili peppers can be evaluated by using nano-chitosan, which combine chitosan and sodium tripolyphosphate (STPP) in certain ratio. The purpose of this study was to determine the impact of nano-chitosan on maintaining the quality of C. frutescens L., the optimal ratio of chitosan to STPP for preserving the quality of C. frutescens L. after harvest, and the shelf life of C. frutescens L. treated with nano-chitosan after harvest. This study employed a completely randomized design (CRD) and included four treatments: P0 (control), P1 (0.2% nano-chitosan, 1:3 ratio), P2 (0.2% nano-chitosan, 1:4 ratio), and P3 (0.2% nano-chitosan, 1:5 ratio), which conducted for 16 days. Weight loss, water content, texture, color, and percentage of damage are the research variables in this study. The ANOVA test was used to examine the data, followed by the DMRT test. The results indicated that nano-chitosan could maintain the weight, water content, texture, and color of chili peppers. The optimal ratio of chitosan to STPP to retain the quality of postharvest C. Frutescens L. is 0.2% nano-chitosan (chitosan: STPP= 1:5), and nano-chitosan can maintain the quality of C. Frutescens L. for up to 16 days.
Pengaruh Kombinasi Pupuk daun dan Nano silika terhadap Pertumbuhan Anggrek (Dendrobium sp.) pada Subkultur secara In Vitro Imroatul Khasanah; Erma Prihastanti; Endah Dwi Hastuti; Agus Subagio
Jurnal Akademika Biologi Vol. 5 No. 3 Juli 2016
Publisher : Departemen Biologi, Fakultas Sains dan Matematika Undip

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Abstract

Orchid is one of the horticulture commodities that are very important in international trade. The problem that is commonly found in the plant tissue culture is hyperhydricity which causes the growth of plant to be too slow. Which is also a problem in acclimatization. Leaf fertilizers contain macro and micro nutrient that promote plant growth. Nano silica is a nutrient which is needed by monocotyl plants to support growth and prevent deficiency or poisoned nutrient. The aim of this research is to know the effects the combination of leaves fertilizer with nano silica and know optimal concentration of  leaves fertilizer and nano silica combination to growth of orchids (Dendrobiumsp) in subculture. This research used Completely Randomize Factorial Design (CRFD) (4x2) with four replication. First factor is leaves fertilizer (G) consists of four extent that is G0: 0,000 g/l; G1: 0,250 g/l; G2: 0,375 g/l; G3: 0,500 g/l. Second factor is nano silica (N) that consists of two extent that is N0: 0 ppm; N1: 20 ppm. The parameters which were measured in this research are number of leaves, plant height, number of roots, and the number of shoots. The data were analyzed by Analysis Of Variance (ANOVA) and continued with Duncan’s Multiple Range Test (DMRT) in extent 95%. The results of this research show that there are effects of interaction between leaves fertilizer and nano silica to the amount of roots. Leaves fertilizer does not really affect the orchid but it tends to increase plant height, the amount of shoots and orchid performance. Nano silica does not really affect the orchid but it tends to increase the amount of leaves, plant height and orchid performance. Keyword: Growth, subculture, concentration, leaves fertilizer, nano silica
Pengaruh Penggunaan Binder terhadap Densitas dan Kalor Pembakaran Briket dari Limbah Sagu Hendri Widiyandari; Wahyu Setiabudi; Agus Subagio; Sri Haryanti; Parsaoran Siahaan; Heru Tjahjana
INDONESIAN JOURNAL OF APPLIED PHYSICS Vol 3, No 02 (2013): IJAP VOLUME 03 ISSUE 02 YEAR 2013
Publisher : Department of Physics, Sebelas Maret University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.13057/ijap.v3i02.1270

Abstract

Biomass fuel such as briquette is one of an alternative energy regarded to the shortage of the fosil fuel and rising its prices. The byproduct of sago starch industry is the waste that remain the environmental problem because of the odor. However this agricultur waste such as trunk cortex and fibre has a potential application as a raw material for briquette.The fibre and trunk cortex act as matrix material of briquette. The utilizing of sago waste as a biomass briquette and the effect of ratio of matrix/binder to the density, time of compustion and gross heat of the briquette have been elucidated sistematically. The analyzing of gross heat using adiabatic calorimetry indicated that the briquette prepared with the ratio of binder/matrix of 3:4 (mass ratio) had the maximum value of 3929.5 kal/g. The duration of combusion was proposional with density of the briquette.